Gayle DeLong, age 10, of Lancaster, Pennsylvania, for her question:

Are all the planets on the same level?

The nine planets all travel around the sun at their own speeds and at their own set distances from the sun. And their orbits are more or less level with the sun's equator. Seen from outer space, in the direction of the North Star, our Solar System would look like a heavenly hoedown of whirling planets shaped somewhat like a saucer. From afar, eight of their orbits would seem to be fairly level with the wide waist of the sun.

A closer view would reveal variations in this neat pattern. Around the rim of the Solar System, the orbit of Pluto is tipped at a very steep angle. One side is quite a bit higher and the other side quite a bit lower than the sun's equator. We call this sort of tilting inclination and Pluto's orbit has an inclination. of 17 degrees: Little Mercury, closest to the sun, has an inclination of 7 degrees sad the inclination of Venus sore than 3 degrees. All the other planetary orbits are within one or two degrees, or almost on a level plane.